Background: Atypical ductal hyperplasia (ADH) is diagnosed in 4% to 10% of directional vacuum-assisted stereotactic biopsies (DVABs) performed for microcalcifications. Since the underestimation rate varies from 7% to 36%, surgical excision is still recommended, although some authors have tried to identify a subset of patients who can be spared surgery.
Methods and results: In this study, we analyzed a retrospective series of 300 patients with ADH on 11-gauge DVAB. The only 4 events that occurred (3%) in 135 of 184 patients (61%) who were followed may not be due to underestimation. Comparing the diagnoses on DVAB and surgical excisions for 116 patients (39%), we identified 3 subsets of patients: no underestimation (size <6 mm and complete removal), low rate of 4% (< or =2 foci ADH in microcalcifications either <6 mm with incomplete removal or > or =6 mm and <21 mm), and high rate of 36% to 38% (>2 foci ADH in microcalcifications either <6 mm with incomplete removal or > or =6 mm and <21 mm, lesion size > or =21 mm).
Conclusions: Our results suggest that strict follow-up can be a safe option for the first 2 groups of patients, but that surgical excision is mandatory for patients from the third group.